Portion of a drill bit



FIG. 1 is a perspective view of a portion of a drill bit showing my new design;

FIG. 2 is an enlarged front view thereof;

FIG. 3 is a partial cross-sectional view of a portion of the bit of FIG. 2 taken along line 3—3 of FIG. 2; and,

FIG. 4 is a top view thereof.

The broken lines shown in the drawings are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a portion of a drill bit, as shown and described. 